#include<iostream.h>
#include<string.h>
void main()
{ char s[20], v[]="aeiouAEIOU";
  int i,j;
  cin>>s;
  i=0;
  while(strchr(v,s[i])!=0 && i<strlen(s)) i++;
  j=strlen(s)-1;
  while(strchr(v,s[j])==0 && j>=0) j--;
  if(i>=strlen(s) || j==-1) cout<<"imposibil";
  else
  { char aux=s[i];
    s[i]=s[j];
    s[j]=aux;
    cout<<s;
  }
}